I was 30 minutes into one of the hardest exercise classes I’d ever tried. We were doing burpees, a movement I was still getting used to, lowering our bodies to the ground and then jumping in the air. Sweat was pouring down my face, my heart was pounding, and I was thinking, Wow, body, look at you go.

And then the instructor called out through her headset: “Who here sinned over the weekend and needs to burn off those calories?”

Whomp. My body, which had been so willing to work hard a moment before, was utterly unmotivated. My form got sloppy. My jump less energetic.

“Woo!” Several people in the class called back.

But I had no woo in me. I spent the rest of the class doing as much as I physically could while also dealing with a barrage of thoughts: What bad things did you eat? These people control themselves, you’re just a slob, that’s why you can’t keep up. If you came to class every day, you’d be thin, and you’d never eat a bad thing again.

I knew when I joined a gym I would be surrounded by weight loss and diet culture messages, something I’d worked hard to eliminate elsewhere in my life. Did I even have a right to be upset? I thought. Aren’t comments like these just part of the deal?

I posted this particular instructor’s comments on my Facebook, asking friends what I should do.

Through my post, I learned I wasn’t the first person to be thrown off by comments like these.

One friend shared that she’d left a gym because of shaming comments an instructor made. My former dance instructor wrote that she quit personal training at her gym because these attitudes were so pervasive. But, they advised, talking to the offending trainer in question one-on-one was likely to be more effective.

I decided that when I found find myself in a class with her again, I would say something. I’d tell her about my own struggles, that exercise has been a place of healing for me but that it’s a fragile balance, that I understand her desire to motivate but that I believed she could find other ways of doing it.

The problem was I didn’t find myself in a class with her again.

I started avoiding this instructor, then group classes entirely—and finally, the gym.

At first, skimming over her classes in the schedule wasn't a conscious decision. But soon I realized I was avoiding her, choosing other teachers in her place. I didn’t want to put myself in a situation where I might run into body-shaming commentary again. For a while I flirted with other classes, then stayed mostly in self-directed areas of the gym. But I couldn't shake the fact that more and more diet messaging seemed to be popping up around the gym, with promotional offers encouraging members to lose weight over the holidays. After a trainer approached me on the treadmill to discuss the promotion, I stopped going entirely.

Ultimately, I didn’t like how much mental energy I was dedicating to un-doing these negative messages.

It surprised me that a small comment could affect me so much—I can only imagine the kind of damage statements like those make on people who are recovering from eating disorders, who don't feel that their bodies are within the typical narrative of “fit,” or who are learning to push their physicality for the first time.

If it had been a different point in my life, I might have stopped moving altogether. I might have fallen back into my old restricted eating patterns. Instead I chose to move in different ways, taking walks around the park, going on hikes, loading HIIT workouts on my computer, and just trying to treat my body well.

I never told the instructor her comment bothered me. But I hope fitness instructors become more mindful of their motivation techniques. I hope they see that they’re working in a remarkably vulnerable space for people, one fraught with pre-judgements and baggage and daunting tipping points. I hope they understand that movement is powerful, and then they speak and act accordingly.